Irving Langmuir

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Irving Langmuir at home (c. 1900).
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Irving Langmuir at home (c. 1900).

Irving Langmuir (January 31, 1881 in Brooklyn, New York - August 16, 1957 in Woods Hole, Massachusetts) was an American chemist and physicist. His most noted publication was the famous 1919 article "The Arrangement of Electrons in Atoms and Molecules" in which, building on Gilbert Lewis's cubical atom theory and Walther Kossel's chemical bonding theory, he outlined his "concentric theory of atomic structure".[1]

While at General Electric, from 1909-1950, Langmuir advanced several basic fields of physics and chemistry, invented the gas-filled incandescent lamp, the hydrogen welding technique, and was awarded the 1932 Nobel Prize for Chemistry for his work in surface chemistry. He was the first industrial chemist to become a Nobel laureate. The Langmuir Laboratory for Atmospheric Research near Socorro, New Mexico was named in his honor.

His study of ionized gases led his coining of the term "plasma".

Contents

Life

Irving Langmuir was born in Brooklyn, New York on January 31, 1881. He was the third child of four of Charles Langmuir and Sadie, née Comings. During his childhood, Langmuir's parents encouraged him to carefully observe nature and to keep a detailed record of his various observations. When Irving was eleven, it was discovered that he had poor eyesight. When this problem was corrected, details that had previously eluded him were revealed. Because of this, his interest in nature and the various complications of nature was heightened.

During his childhood, Langmuir was greatly influenced by his older brother, Arthur Langmuir. Arthur was a research chemist who encouraged Irving to be curious about nature and how things work. Arthur helped Irving set up his first chemistry lab in the corner of his bedroom, and he was content to answer the myriad of questions that Irving would pose. Langmuir's hobbies included mountaineering, skiing, piloting his own plane, and classical music. In addition to his professional interest in the politics of atomic energy, he was deeply concerned about wilderness conservation.

Education

He attended his early education at various schools and institutes in America and Paris (1892-1895). He graduated with a B.S. in metallurgical engineering from the Columbia University School of Mines in 1903. He earned his Ph.D. degree in 1906 under Nobel laureate Walther Nernst in Göttingen, for research done using the "Nerst glower", an electric lamp invented by Nerst. His doctoral thesis was entitled “On the Partial Recombination of Dissolved Gases During Cooling.” He later did postgraduate work in chemistry. Langmuir then taught at Stevens Institute of Technology in Hoboken, New Jersey, until 1909, when he began working at the General Electric research laboratory (Schenectady, New York). In 1912, he married Marion Mersereau. They had a son, Kenneth, and a daughter, Barbara.

Scientific work

His initial contributions to science came from his study of light bulbs (a continuation of his Ph.D. work). His first major development was the invention of the diffusion pump, which ultimately led to the invention of the high-vacuum tube. A year later, he and colleague Lewi Tonks discovered that the lifetime of a tungsten filament was greatly lengthened by filling the bulb with an inert gas, such as argon. He also discovered that twisting the filament into a tight coil improved its efficiency. These were important developments in the history of the incandescent light bulb.

As he continued to study filaments in vacuum and different gas environments, he began to study the emission of charged particles from hot filaments (thermionic emission). He was one of the first scientists to work with plasmas and was the first to call these ionized gases by that name, because they reminded him of blood plasma.[2]

He introduced the concept of electron temperature and in 1924 invented the diagnostic method for measuring both temperature and density with an electrostatic probe, now called a Langmuir probe and commonly used in plasma physics. The current of a biased probe tip is measured as a function of bias voltage to determine the local plasma temperature and density. He also discovered atomic hydrogen, which he put to use by inventing the atomic hydrogen welding process; the first plasma weld ever made. Plasma welding has since been developed into gas tungsten arc welding.

Later years

Following World War I Langmuir contributed to atomic theory and the understanding of atomic structure by defining the modern concept of valence shells and isotopes.

He joined Katherine Blodgett to study thin films and surface absorption. They introduced the concept of a monolayer (a layer of material one molecule thick) and the two-dimensional physics which describe such a surface. In 1932 he received the Nobel Prize for Chemistry "for his discoveries and investigations in surface chemistry."

In 1938, Langmuir's scientific interests began to turn to atmospheric science and meteorology. One of his first ventures, although tangentially related, was a refutation the claim of entomologist Charles H. T. Townsend that the deer botfly flew at speeds in excess of 800 miles per hour. Langmuir estimated the fly's true speed at 25 miles per hour.

During World War II, Langmuir worked on improving naval sonar for submarine detection, and later to develop protective smoke screens and methods for de-icing aircraft wings. This research led him to theorize that the introduction of dry ice and iodide into a sufficiently moist cloud of low temperature could induce precipitation (cloud seeding); though in frequent practice, particularly in Australia and the People's Republic of China, the efficacy of this technique remains controversial today.

In 1953 Langmuir coined the term "pathological science", describing research conducted with accordance to the scientific method, but tainted by unconscious bias or subjective effects. This is in contrast to pseudoscience, which has no pretense of following the scientific method. In his original speech, he presented ESP and flying saucers as examples of pathological science; since then, the label has been applied to polywater and cold fusion.

After a short illness, he died of a heart attack in 1957. His obituary ran on the front page of the New York Times.

References

  1. ^ Langmuir, I. (1919). "The Arrangement of Electrons in Atoms and Molecules", Journal of the American Chemical Society. Vol. 41, No. 6, 861.
  2. ^ What is Plasma? - Coalition for Plasma Science

See also

Patents

  • Langmuir, US patent 1180159, "Incandescent Electric Lamp"
  • Langmuir, US patent 1244217, "Electron-discharge apparatus and method of operating the same"
  • Langmuir, US patent 1251388, "Method of and apparatus for controlling x-ray tubes"

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